I'm pretty sure by now the various "classes" of service offered by Lyft and Uber are instead just ways for the customer to donate money to Lyft and Uber. There's no difference in what kind of yahoo shows up in what kind of beater.
That and I guess UberXL - otherwise it’s pretty fungible.
The interesting bit is that black is often pretty much the same price a UberX about a third of the time.
https://en.wikipedia.org/wiki/Hackney_carriage
I think this would be similar to the medallions of yellow NYC cabs
This needs more driver quality insight because e.g. passenger gets in your vehicle, you drive them to some secluded spot and their body is found the next morning - there's no records for murder cops to start from, unless there was a witness there may not even be a description of your vehicle. The UK has had this happen, but it's very rare because the sort of person likely to escalate to murder is not going to get licensed.
In contrast a mini-cab or Uber-style driver has records of who was dispatched to pick up somebody, where they were picked up etc. So if you take to murdering your fares the murder detectives will show up at your door with company records implicating you.
In my experience in west europe, booking a uber XL you usually get a full size van (vw caravelle/multivan, Mercedes v-class or a bigger Renault Trafic) with usually 7 to available seats.
Booking a uberXL in Mexico City gets you a miniSUV with only 4 available seats and if you get too much checked luggage it goes on a roof rack.